Treecko-- He saw the one that was offered to May!
Are you countiong evolutions?
Yes I am. Evolutions count. In fact, a lot of the evos Ash got were definitley seen/battled by him way before he got the evo. Basically why I asked the question is because I remembered how there were so many of those.
EDIT: Breakdown -
Kanto:
3 have been mentioned. 1 remains.
Johto:
4 have been mentioned. 4 remain.
Hoenn:
1 have been mentioned. 5 remain.
Sinnoh:
3 have been mentioned. 4 remain.
Seviper's leading so far.